This invention relates to transformers, especially to transformers in which it is desired to have particular ratios of input voltage to one or more output voltages. This ratio is usually determined by the relative number of turns, or xe2x80x9cturns ratioxe2x80x9d of the various windings of the transformer, but in prior art transformers this is restricted to whole number ratios.
As the operating frequency of transformers increases, and the operating voltage decreases, single turn windings, or windings having only a few turns, are becoming more and more common. With a large number of turns, it is fairly easy to get an arbitrary ratio of the input to the outputs, such as 127 to 13 to 7.
With a single turn secondary, there are large gaps between the available ratios using whole numbered turns. As an example, there is a big difference between a 4 to 1 and a 3 to 1 turns ratio, but nothing in between is commonly available. There is some prior art teaching half turn windings. U.S. Pat. No. 5,999,078, Herbert, teaches a transformer module with a xe2x80x9chalf turnxe2x80x9d secondary. U.S. Pat. No. 3,768,055, Oliver, also teaches a xe2x80x9chalf turnxe2x80x9d secondary winding. U.S. Pat. No. 6,137,392, Herbert, has embodiments having a xe2x80x9chalf turnxe2x80x9d secondary winding.
It is an object of the present invention to be able to use intermediate fractional turns, for example 6.3 to 3.7 to 1. A flux distribution winding can be added to two or more parallel legs of a transformer to apportion the flux among them. A winding on a particular leg with a portion of the total flux will have an equivalent winding which is a fraction proportional to portion of the flux.